1. (Science: zoology) One of the Insecta; especially, one of the hexapoda. See insecta.
The hexapod insects pass through three stages during their growth, viz, the larva, pupa, and imago or adult, but in some of the orders the larva differs little from the imago, except in lacking wings, and the active pupa is very much like the larva, except in having rudiments of wings. In the higher orders, the larva is usually a grub, maggot, or caterpillar, totally unlike the adult, while the pupa is very different from both larva and imago and is inactive, taking no food.
2. (Science: zoology) Any air-breathing arthropod, as a spider or scorpion.
3. (Science: zoology) Any small crustacean. In a wider sense, the word is often loosely applied to various small invertebrates.
4. Any small, trivial, or contemptible person or thing. Insect powder,a powder used for the extermination of insects; especially, the powdered flowers of certain species of pyrethrum, a genus now merged in Chrysanthemum.
Synonym: persian powder.
Origin: F.insecte, L. Insectum, fr. Insectus, p.p. Of insecare to cut in. See section. The name was originally given to certain small animals, whose bodies appear cut in, or almost divided. Cf. Entomology.